Clark Fork River Fishing Forecast
Fly fishers plan Montana trips on the Clark Fork River because it stacks credible wading access, recognizable insect cycles, and trout that respond when flows align. Expect classic freestone rhythm: push during stable or dropping flows after fronts, then back off when the river spikes and color returns in 24–48 hours. River-specific intel: The Clark Fork River is Montana's largest river by volume, recovering from historic mining impacts. Good populations of brown, rainbow, and cutthroat trout now thrive. USGS gauge 12340500 tracks live flow and temperature for planning wade or float days.
Spring-fed Clark Fork River is flowing at 1210 CFS CFS with surface temps near 59°F°F — 6/10 today. Top pick: a Adams.
Open 3rd Sat in May — Nov 30
Western District. Some sections have special regs due to mine remediation
Forecast and on-page guide updated September 8, 2026 (UTC). Open the app for hourly conditions.
Today's Fishing Conditions
Good
Updated 10:20 PM
59°F
1210 CFS
4 AM - 6 AM
Adams
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September Hatches
BWO
Mayfly
Overcast conditions prime. Extended season.
October Caddis
Caddis
Fall caddis. Orange patterns effective.
Caddis
Caddis
Evening caddis emergence. Summer staple.
Hopper
Terrestrial
Terrestrial season. Hopper patterns along banks.
September Fishing Tactics
Primary Targets
Recommended Tactics
Excellent fall fishing. Browns aggressive.
Year-Round Fishing Guide
| Month | Water Temp | Tactics |
|---|---|---|
| January | 32-38°F | Deep nymphing, Midges, Streamers |
| February | 33-40°F | Midges, Small nymphs, Deep pools |
| March | 36-45°F | BWO dries, Streamers, Early stonefly nymphs |
| April | 40-50°F | Skwala dries, BWO patterns, Streamers |
| May | 45-55°F | Mother's Day Caddis, Nymphing, Streamers |
| June | 50-60°F | Salmonfly dries, Golden Stones, PMDs |
| July | 55-68°F | PMDs, Hoppers, Caddis, Attractor dries |
| August | 55-70°F | Hoppers, Tricos, PMDs, Terrestrials |
| September(Now) | 48-58°F | BWOs, Streamers, Hoppers |
| October | 40-50°F | Streamers, BWOs, Egg patterns |
| November | 35-42°F | Streamers, Deep nymphs, Egg patterns |
| December | 32-38°F | Deep nymphs, Midges, Slow presentations |
Quick Facts
Brown Trout, Rainbow Trout, and Westslope Cutthroat Trout
freestone
48°F - 58°F
What Makes the Clark Fork River Unique?
Signature hatch or window
BWO (Mayfly) is a headline hatch to watch in September. Peak activity often tracks 42–55°F water temps.
Distinctive access
Deer Lodge: Upper river access.
Rules anglers miss
Regulations vary by section.
When is the Best Time to Fish Clark Fork River?
Spring
Stoneflies begin emerging. Watch for runoff.
Summer
Prime season with diverse hatches.
Fall
Brown trout become more active. Good streamer fishing.
Winter
Challenging but fishable near Missoula.
Recommended Equipment for Clark Fork River
Rod
9-foot, 5 or 6-weight for most fishing.
Line
Floating line for dries. Sink-tip for streamers.
Leader & Tippet
9-foot tapered leader, 4X-5X tippet.
Waders
Breathable waders. Wade carefully in bigger water.
Essential Flies
How to Fish Clark Fork River: Tips & Tactics
The Clark Fork River is Montana's largest river by volume, recovering from historic mining impacts. Good populations of brown, rainbow, and cutthroat trout now thrive.
Best Times of Day
Summer offers the best fishing with diverse hatches. The river fishes well throughout the day. Fall brings larger fish on the move.
Recommended Techniques
Float fishing covers the big water. Match the hatches when active. Streamers are effective for larger fish. Wade fishing at access points.
Water Conditions
The Clark Fork has recovered significantly from Superfund cleanup. The Missoula section is easily accessible. The Alberton Gorge offers adventure.
Fly Selection
Caddis patterns are essential. Stoneflies in spring and summer. Streamers for brown trout. BWOs and PMDs for mayflies.
Access Points & Parking for Clark Fork River
Deer Lodge
Upper river access.
Missoula
Urban fishing through the city.
Alberton Gorge
Canyon section with whitewater.
Superior
Lower river access.
Spawning Seasons
Please respect spawning fish and their redds. Avoid fishing over actively spawning trout.
Brown Trout
Spawn months: October, November
Night spawning common. Males become very dark with pronounced kype during spawn.
Rainbow Trout
Spawn months: March, April
Resident rainbow trout spawn in smaller tributaries and tend to build smaller redds than steelhead.
Cutthroat Trout
Spawn months: May, June, July
Spring spawners. Timing varies by subspecies and elevation - coastal populations spawn earlier (Feb-Mar), inland populations later (May-July). Eggs develop for 6-7 weeks before hatching.
Westslope Cutthroat
Spawn months: June, July
Native to northern Rocky Mountain streams. Spawn later than other cutthroat due to high-elevation habitat and colder water. Particularly sensitive to hybridization with rainbow trout.
Optimal Fishing Conditions
Optimal Flow
3000 - 8000 CFS
Best fishing conditions
Optimal Water Temperature
50° - 65°F
Ideal for active trout
Clark Fork River Fishing Regulations
Season
Open year-round.
Limits
Check Montana FWP for current regulations.
Special Regulations
Regulations vary by section.
Bait Restrictions
Artificial flies and lures only in some sections.
Notes
The Clark Fork continues to recover and improve.
Always verify current regulations with Montana fish and wildlife agency before fishing. Regulations can change annually.
Fly Shops & Guides Near Clark Fork River
Local Fly Shops
- Grizzly Hackle - Missoula
- Missoulian Angler - Missoula
- Clark Fork River Guide Service
Guide Services
- Grizzly Hackle Guides
- Clark Fork Guide Service
- Missoula Fly Fishing
Other Rivers You Might Like
Popular forecasts outside Montana—great for trip planning and comparing conditions.
Other Montana Trout Rivers
Bitterroot
Blackfoot
Yellowstone (inside YNP)
Madison
Missouri (below Holter)
Clark Fork River — frequently asked questions
When is the best time to fish the Clark Fork River?
Excellent fall fishing. Browns aggressive.
What flies should I bring to the Clark Fork River?
For the Clark Fork River (freestone), carry: Elk Hair Caddis, Stimulator, Pat's Rubber Legs, Woolly Bugger, BWO.
What water temperature is best for trout on the Clark Fork River?
On the Clark Fork River, trout hold between 50° and 65°F. In summer, expect temps to swing with air temperature — fish early.
Do I need a fishing license for the Clark Fork River?
Yes — you need a valid Montana fishing license to fish the Clark Fork River. Local season: Open year-round.. Daily limit: Check Montana FWP for current regulations..
What hatches should I watch for on the Clark Fork River in September?
BWO is the signature hatch on the Clark Fork River in September. Match size and adjust leader size to 5X-6X. The fish key in on the emergence during low-light hours, so plan to be on the water at first light.
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